UGREEN 40Gbps M.2 NVMe SSD Enclosure, NVMe Enclosure with Cooling Fan, Aluminum M.2 Enclosure Support USB4/TB4 , UASP & TRIM, SSD Enclosure Compatible MacBook M1 M2 M3 M4 Pro/Max, Up to 3700MB/s

Summary: Looks good, feels good, performs amazing - IF YOU ENABLE WRITE CACHING! This SSD enclosure is amazing, its really fast (not quite the 40Gbps advertised limit - but it is expected not to hit this as this is a theoretical raw transfer rate that is also bidirectional), it also had a very good build quality, and feels very premium. To all those reading the comments and feeling torn due to the reviews that report slow write speeds - fear not! I also had my doubts; when testing the product for the first time (with a Kioxia gen 4 drive) I had the same issues (see picture 1). After doing a little digging I found that under Device Manager > Disk Drives > (NVME Drive in your enclosure) > Properties > Policies: "Enable write caching on this device" had defaulted to off. After turning this on (see picture 2), and testing again, the expected speeds instantly shot up to expected speeds (see pictures 3 and 4). Note: Enabling write caching this way is specific to Windows, I am unsure how this setting defaults on Apple devices, but I am confident that a synonymous setting exists.

I like, it feels very well made and is a decent weight The fan works and is quiet Works with my Time Machine The included screw and attachment process - much preferred to a tool less design. Looks good - not an issue for me but it does I don’t like, the heat. This is hot when in us and when idle. This may be down to the thermal pad, not doing a job - It is TOO THIN. Currently I have no other pads but have ordered a pack - update to follow Currently NOT attached 24/7 as I don’t wish to consistently run it hot Long term, I may get a couple of stainless steel blocks 80x30x30 and use those as heat soaks Update, Had this a week or so now, running cooler than it originally was, I suspect that’s due to the whole system now registered together. It does run faster when connected to my hub, a bit strange but not significant.

Operates well with very fast NVMEs. Runs warm when idling and hot when working. The fan is quiet, almost silent. The rubber enclosure protector is not necessary unless to limit vibration, which I haven't experienced. It impedes air intake for the fan and reduces heat dissipation. Works fine without it.

It looks the part & seems well built (and quiet, I have read other people found it noisy). Inserted a Samsung 990 NVMe M.2 SSD 4TB PCIe 4.0 7450/6900. Only performed at 10Gbps (while it worked) NOT 40 Gbps. Tried CrystalDiskMark 8 (see image). Expected to see round 3600/3400 for the Samsung in this caddy. Tried read/write large video files - again only reached just under 10Gbps speed (960 MB/s read 750 MB/sec write). Windows refuses to recognise it now. - can't do anything with it (even on a 10Gbps port). Using Windows 11 Pro up to date on a Ryzen 16-core PC & all drivers up to date. Tried on both of the Asus motherboard Thunderbolt 4/USB4 ports. Another Thunderbolt 4 device I have works ok. The Samsung is ok, worked in a UGREEN 10Gbps caddy on a 10Gbps PC port at expected speeds for that caddy. (But of course that defeats the objective). Returned, and as usual Amazon handled it promptly (thanks). Going to try a "SSK 40Gbps M.2 NVMe SSD Enclosure, USB4 NVMe Caddy USB C for Thunderbolt 3/4". UPDATE: 9th March 2025 Windows 11 indicates that it's not a compatible USB4 device. While I only give 1 star that's because the device does not work for my PC - it may work for you. The device itself is well built and, I suspect, very capable if you have the right USB4 port (or one labelled 40Gbps). It's has taken some time to determine what is going on, but it boils down to this ... USB4 can be either 20 Gbps or 40 Gbps, depending on the specific device and its capabilities; the standard supports both speeds, with 40 Gbps being the maximum transfer rate achievable with the latest USB4 technology. Key points about USB4 speeds: 20 Gbps: Considered a "base" speed for many USB4 devices. 40 Gbps: The highest possible data transfer rate for USB4, achieved with specific compatible devices and cables. NB: In the future the standards talk about 80Gbps I think the issue I have is EITHER my ports are a USB4 20Gbps port (even though it's Thunderbolt 4 40Gbps), OR it's the mine field of "compatible devices". My Asus motherboard (on a Ryan 16-core) has an early adoption of Thunderbolt 4/USB4 ports. My Thunderbolt 4 & 3 devices work perfectly on the Thunderbolt 4 ports. Also any USB 3 Gen 2 (10Gbps) device works as expected (as does any 5Gbps USB device). I suspect USB 3 Gen 2x2 (20 Gbps) will work - yet to be confirmed. The problem is USB4 devices only - and the USB standards - they are confusing. I notice that recent Asus motherboards describe ports as "10Gbps" or "20Gbps" which avoids confusion. (Not sure if that's because of new standards). Any 40Gbps NVMe caddy is a gamble for Windows users depending on the capability of your PC USB4 port. I don't know about Mac users. Returning the item to Amazon (whose service has always been excellent for me). I have two UGREEN 10Gbps M.2 NVme caddy and they work perfectly (speed as expected). I have tried SSK 40Gbps M.2 NVMe SSD Enclosure (as mentioned earlier) and it has the same issue as this product. So, I will now try a UGREEN M.2 NVMe Enclosure, 20Gbps - I suspect it will work perfectly.

Tested with Seagate Fireside 530 (heatsink version, but removed) and Macbook M1 Max. Speeds are OK - top out at 3500 write and 4000 read. Which is not exactly the theoretical 40gbps but much higher than USB3.2 v2 10gbps standard. Sturdy but small. Heats up to 40 Celsius on long-term operations but stays within 36-38 on average. Cooling fan usefulness is not clear, feels like a gimmick. Thermal pad is thin, so probably won't even touch the heatsink cover, I've used both suppliad and the one from my NVME heatsink. [ ! ] Important - use supplied cables only for advertised speeds.

As others have mentioned, it feels and looks premium and I'm getting good speeds on a Mac Studio M1 Ultra (see screenshot). However, it gets hot and the fan ramps up and is noisy. I mainly work with audio and I couldn't use this while working on audio in the same room - it's louder than my entire Mac Studio which is a bit silly. It should be the type of flat fan similar to what's in a MacBook rather than a useless normal 2cm fan. The ramping up and down of the fan is also annoying. It's just sat there after a file transfer with the fan ramping up and down, not even in use. I'm pretty sure the fan isn't helping things much, which seems like a waste. If it's going to make noise, at least make it do something. Further, the drive sits at an angle, so only about 25% of the thermal pad is touching anything with a WD SN850X 2GB NVMe drive. Pretty silly, basic stuff. I added a bit of extra thermal pad that I had, unsure if I'm really helping anything or not. Thankfully, I bought this for video editing, where I don't really care about noise as much. So I'll leave it unplugged unless I'm working on video. While I'm happy with the speed, I wouldn't buy another unless it was for video or photo editing.

Very well made with thermal sticker and cable. As advertised, at least for my needs. I am a Mac user hence my review focused on that OS. Both M1Max and M3Max MBPro laptops show 2100MB/s read speed and 2450MB/s write. Both laptops have TB4 ports with max theoretical speed 3000MB/s. The fastest supported NVMe drive must be Gen4. SSD NVMe PCI Gen 5 IS NOT SUPPORTED! My drive is WDBlue NVMe PCIe Gen4, 2400MB/s and is well supported by this enclosure, bottlenecking the max speeds I can achieve. I highly recommend it for TB4 systems and at least 3000MB/s drives.

I tried an Acasis first but it promptly failed (the one with a fan). This however has already been running fine for much longer than that one lasted, and even has considerably faster read and write speeds! I also have a Zike, which has slightly faster write speeds but this actually just beats the Zike's read speeds for me. Highly recommended - uGreen have impressed me several times now. From my limited experience Acasis is slow and unreliable, but you can't go wrong with uGreen or Zike.